That’s pretty strange though, I don’t think I’ve seen a subway with a time table before. It’s too frequent for it to matter in the first place, you just need to know when the next train towards your destination is coming!
- due to all the merging in and out throughout the system, trains need to be in the right place at the right time or merging delays will cascade throughout the system
- for purposes of employee scheduling, you need to make sure that the right employees are in the right place at the right time; generally a train leaving a terminal is being driven by a crew that had to come in from somewhere else.
Isn't that a different idea than a timetable? "We're aiming for one train every 10min" and "there's a train at 12.10, 12.20, 12.30" are similar, but not quite the same. You can get your approximation without a timetable though.
Tracked vehicles require centralised traffic management and scheduling as they cannot casually overtake one another as street traffic can, and setting switching points and clearing control blocks is required for safety.
Passengers transferring to other lines or transit modes may also appreciate predictability.
One could make the argument that a train showing up ten minutes late vs one on time doesn't really matter to a person so long as it shows up within a reasonable time of them getting to the station and it still takes them to their destination on time. If the headways are five minutes and every single train is running at the same speed just five minutes late, this is a distinction that doesn't matter to the passenger.
